Need optimax help.

[trex]

I ordered 6 pistons from Promarine. They said they fit my 09 225 pro. My mechanic put it together and said the pistons don’t clear the heads. I ordered 6-7500 series bored .015 over. Anything that y’all experts can advise me? Seriel number is 1B7115289.

[Dave S]

The early pistons were flat..... the newer were domed........just a year ....### changing prob.....Call Chazzzzz.

[FORBESAUTO]

I’m pretty sure there is different fuel pockets and some are raised more than others, some oval and some round. Looks like pro marine only offers wiseco for the 09, the 3212 series. Check them out and see if those look like what you need

[trex]

So can i put heads on from a newer motor? What years would have a bigger chamber?

[Dave S]

I think I have the newer heads.......

[FORBESAUTO]

Not 100% sure if there is any issues with swapping heads. I broke out the the book and looks kinda like you got the right pistons. Have ya been able to compare what’s the difference by comparing old pistons? Is it a different in pockets being oval or round? Or just higher edges? What kind of pockets does the new pistons have, maybe can figure out what heads will work from there. I’ve only built s few but havnt swapped parts around to know what works. Main difference I’ve seen is oval and round, and thinking as long as you got matching heads you should be ok.

[trex]

I had oval splash ports. New pistons are dome with round splash port I looked everywhere I can in Promarines book. One area I found suggests a 9100 the other says the 7500. I’m going to call them in the morning, but I’ve had a hard time getting technical info from them.

[trex]

Trying to put a few pics on

[trex]

[FORBESAUTO]

I’ve had good look with help from them. Give them a call, the 9100 do show to be oval. If they help ya out on swapping pistons, I would probably go that route to keep from having a chain reaction of issues by swapping heads. Unless someone who has been there done that chimes in and all transfers flawlessly.

[Motv18]

You did order port and starboard not just 6 of one side? Or they might be getting the side wrong if they haven’t done many.

[trex]

I ordered 3 of each yes. One thing we can’t figure out is it has steel reed pedals and flat pistons. I’m sure about the model number and have checked the head of another blown power head and it’s the same. Is there a chance I don’t have a pro xs, or did they put flat pistons in pro xs in 2008?

[trex]

Chazz at Promarine?

[FORBESAUTO]

Chaz is a 3.0 liter guru on here. Hopefully ole Unc ‘ll chime in and enlighten us

[trex]

I called mercury and they tell me that it’s not a pro xs. It’s a regular 3.0 opti. Now I’m trying to figure out if I can get pro heads and make it work.